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Mirrors > Home > MPE Home > Th. List > cmpfii | Structured version Visualization version GIF version |
Description: In a compact topology, a system of closed sets with nonempty finite intersections has a nonempty intersection. (Contributed by Stefan O'Rear, 22-Feb-2015.) |
Ref | Expression |
---|---|
cmpfii | ⊢ ((𝐽 ∈ Comp ∧ 𝑋 ⊆ (Clsd‘𝐽) ∧ ¬ ∅ ∈ (fi‘𝑋)) → ∩ 𝑋 ≠ ∅) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fvex 6677 | . . . . 5 ⊢ (Clsd‘𝐽) ∈ V | |
2 | 1 | elpw2 5240 | . . . 4 ⊢ (𝑋 ∈ 𝒫 (Clsd‘𝐽) ↔ 𝑋 ⊆ (Clsd‘𝐽)) |
3 | 2 | biimpri 230 | . . 3 ⊢ (𝑋 ⊆ (Clsd‘𝐽) → 𝑋 ∈ 𝒫 (Clsd‘𝐽)) |
4 | cmptop 21997 | . . . . 5 ⊢ (𝐽 ∈ Comp → 𝐽 ∈ Top) | |
5 | cmpfi 22010 | . . . . 5 ⊢ (𝐽 ∈ Top → (𝐽 ∈ Comp ↔ ∀𝑥 ∈ 𝒫 (Clsd‘𝐽)(¬ ∅ ∈ (fi‘𝑥) → ∩ 𝑥 ≠ ∅))) | |
6 | 4, 5 | syl 17 | . . . 4 ⊢ (𝐽 ∈ Comp → (𝐽 ∈ Comp ↔ ∀𝑥 ∈ 𝒫 (Clsd‘𝐽)(¬ ∅ ∈ (fi‘𝑥) → ∩ 𝑥 ≠ ∅))) |
7 | 6 | ibi 269 | . . 3 ⊢ (𝐽 ∈ Comp → ∀𝑥 ∈ 𝒫 (Clsd‘𝐽)(¬ ∅ ∈ (fi‘𝑥) → ∩ 𝑥 ≠ ∅)) |
8 | fveq2 6664 | . . . . . . 7 ⊢ (𝑥 = 𝑋 → (fi‘𝑥) = (fi‘𝑋)) | |
9 | 8 | eleq2d 2898 | . . . . . 6 ⊢ (𝑥 = 𝑋 → (∅ ∈ (fi‘𝑥) ↔ ∅ ∈ (fi‘𝑋))) |
10 | 9 | notbid 320 | . . . . 5 ⊢ (𝑥 = 𝑋 → (¬ ∅ ∈ (fi‘𝑥) ↔ ¬ ∅ ∈ (fi‘𝑋))) |
11 | inteq 4871 | . . . . . 6 ⊢ (𝑥 = 𝑋 → ∩ 𝑥 = ∩ 𝑋) | |
12 | 11 | neeq1d 3075 | . . . . 5 ⊢ (𝑥 = 𝑋 → (∩ 𝑥 ≠ ∅ ↔ ∩ 𝑋 ≠ ∅)) |
13 | 10, 12 | imbi12d 347 | . . . 4 ⊢ (𝑥 = 𝑋 → ((¬ ∅ ∈ (fi‘𝑥) → ∩ 𝑥 ≠ ∅) ↔ (¬ ∅ ∈ (fi‘𝑋) → ∩ 𝑋 ≠ ∅))) |
14 | 13 | rspcva 3620 | . . 3 ⊢ ((𝑋 ∈ 𝒫 (Clsd‘𝐽) ∧ ∀𝑥 ∈ 𝒫 (Clsd‘𝐽)(¬ ∅ ∈ (fi‘𝑥) → ∩ 𝑥 ≠ ∅)) → (¬ ∅ ∈ (fi‘𝑋) → ∩ 𝑋 ≠ ∅)) |
15 | 3, 7, 14 | syl2anr 598 | . 2 ⊢ ((𝐽 ∈ Comp ∧ 𝑋 ⊆ (Clsd‘𝐽)) → (¬ ∅ ∈ (fi‘𝑋) → ∩ 𝑋 ≠ ∅)) |
16 | 15 | 3impia 1113 | 1 ⊢ ((𝐽 ∈ Comp ∧ 𝑋 ⊆ (Clsd‘𝐽) ∧ ¬ ∅ ∈ (fi‘𝑋)) → ∩ 𝑋 ≠ ∅) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 ↔ wb 208 ∧ w3a 1083 = wceq 1533 ∈ wcel 2110 ≠ wne 3016 ∀wral 3138 ⊆ wss 3935 ∅c0 4290 𝒫 cpw 4538 ∩ cint 4868 ‘cfv 6349 ficfi 8868 Topctop 21495 Clsdccld 21618 Compccmp 21988 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1792 ax-4 1806 ax-5 1907 ax-6 1966 ax-7 2011 ax-8 2112 ax-9 2120 ax-10 2141 ax-11 2157 ax-12 2173 ax-ext 2793 ax-sep 5195 ax-nul 5202 ax-pow 5258 ax-pr 5321 ax-un 7455 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-3or 1084 df-3an 1085 df-tru 1536 df-ex 1777 df-nf 1781 df-sb 2066 df-mo 2618 df-eu 2650 df-clab 2800 df-cleq 2814 df-clel 2893 df-nfc 2963 df-ne 3017 df-ral 3143 df-rex 3144 df-reu 3145 df-rab 3147 df-v 3496 df-sbc 3772 df-csb 3883 df-dif 3938 df-un 3940 df-in 3942 df-ss 3951 df-pss 3953 df-nul 4291 df-if 4467 df-pw 4540 df-sn 4561 df-pr 4563 df-tp 4565 df-op 4567 df-uni 4832 df-int 4869 df-iun 4913 df-iin 4914 df-br 5059 df-opab 5121 df-mpt 5139 df-tr 5165 df-id 5454 df-eprel 5459 df-po 5468 df-so 5469 df-fr 5508 df-we 5510 df-xp 5555 df-rel 5556 df-cnv 5557 df-co 5558 df-dm 5559 df-rn 5560 df-res 5561 df-ima 5562 df-pred 6142 df-ord 6188 df-on 6189 df-lim 6190 df-suc 6191 df-iota 6308 df-fun 6351 df-fn 6352 df-f 6353 df-f1 6354 df-fo 6355 df-f1o 6356 df-fv 6357 df-ov 7153 df-oprab 7154 df-mpo 7155 df-om 7575 df-1st 7683 df-2nd 7684 df-wrecs 7941 df-recs 8002 df-rdg 8040 df-1o 8096 df-2o 8097 df-oadd 8100 df-er 8283 df-map 8402 df-en 8504 df-dom 8505 df-sdom 8506 df-fin 8507 df-fi 8869 df-top 21496 df-cld 21621 df-cmp 21989 |
This theorem is referenced by: fclscmpi 22631 cmpfiiin 39287 |
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